horizontal fluid troubles
The manta flow integration isn't working that well.
It seems to be out of focus of current development goals, not sure why.
It has various issues, for example there is no world scale.
So essential a teacup can behave alike an ocean.
in 2.92 there is setting narrowband that might improve the rendering, for beams.
Another bug is that once the cache is made, its not refreshed on each setting change.
If you change some domain settings, you probaply dont see its effect.
What so far worked for me is to change the domain resolution, this forces a new cach rebuild, and new settings get effective. its a pain in the a** to do it like that but i dont know of other options.
Positive about this cache as compared tot he past you dont have to bake all frames before you see the result, and a needle preview option (unmeshed).

Updated answer
Though read the above parts as well.

Note some versions seem to have delete bake option now.
So you can quickly rebake the domain of the fluid. I used an alpha 2.92

For these kind of flows use a planar inflow it's an option which you can enable.
And when you do you can remove the surfaces pointing to unwanted directions (ea sides and the back surface).

Use liquid (not smoke)

Set the grid maybe a bit smaller

There is no need to put it surrounded by a fluid blocking object (if you use surface option), when you still want such an object have at least some surfaces stick out of the blocking object.

An extra trick is to set the object of the domain to smooth shading.
The're often highly detailed and smoothing really finishes it off to get that wet look.


I personally always use the latest alpha versions (its a choice), so i'm not sure if the other verrsions with manta have the free bake and bake buttons on the domain, i never kept track of it, though i think its new ??.
Freebake has the same effect of the altered fluid domain trik, to enforce new cache.
Result with workbench render, (higher cell size in domain) and more sub sampeling, to deal with high speed flows, result :
https://youtu.be/6Ic_pe8W8bY